1. Field of the Invention
The present invention relates to an apparatus for detecting and analyzing adsorbates adsorbed on a solid object such as a catalyzer carrier used in a device for cleaning exhaust gas from an internal combustion engine, a deodorant carrier and the like. The apparatus is used for observing states of adsorption, detecting kinds of the adsorbates, analyzing a adsorption mechanism and evaluating the solid object.
2. Description of Related Art
To observe adsorbates adsorbed on a solid object, and to find out a reaction and adsorption mechanism, an infrared spectrometer has been used in a detection apparatus of this kind. The infrared spectrometer detects an infrared radiation peculiar to an adsorbate from an infrared spectrum of the adsorbate, and, thereby, the kind of the adsorbate is determined and the amount of the adsorbate is measured. As an infrared spectrometer, two types of the spectrometer have been used. One is a Fourier transform infrared spectrometer with diffuse reflectance equipment, and the other is a Fourier transform infrared emission spectrometer. When the former is used, there are some difficulties to detect a specific infrared radiation from an adsorbate having a temperature higher than 500.degree. C. because a total amount of the radiation increases as the temperature becomes higher and the increased amount of the radiation acts as a noise in detection of the specific radiation, decreasing a signal-to-noise ratio.
An example of the detecting apparatus in which the latter spectrometer, i.e., the Fourier transform infrared emission spectrometer is used, is described in Japanese Patent Laid-Open Publication No. Hei-4-115141. In this apparatus, a specimen on which an adsorbate is adsorbed is prepared before observation and it is observed by the spectrometer while heating it in an open space. In this observation, the specimen and an object lens must be placed close enough to each other to receive substantially all radiations from the specimen with a good signal-to-noise ratio. In the publication, however, it is not mentioned how to realize this requirement at a temperature higher than 500.degree. C. In addition, the specimen can be observed only at its static condition because the specimen with the adsorbate has to be prepared before observation and is heated during the observation. In other words, it cannot be observed under the condition where gases formulating the adsorbate are actually flowing. To attain valuable results from the observation and analysis, it is necessary to observe and analyze the adsorbate under the condition where gases are actually flowing.
In order to realize a dynamic observation and analysis, it is considered to place the solid object on which the adsorbate is to be formed in a closed chamber and to make a gas flow in the chamber, and to observe and analyze infrared radiations from the adsorbate through an infrared-transmissive window disposed on a wall of the closed chamber. In this arrangement, it is necessary to place the infrared-transmissive window between an object lens for receiving the infrared radiations and the solid object having a high temperature. The window may be broken by heat from the hot solid object at a high temperature and the gas in the closed chamber may leak to the outside, thereby endangering a safe operation of the observation and analysis.